Role of Hydroxy Group in the Electro-Optical Properties of Polymer-Dispersed Liquid Crystals

In this work, hydroxylated compounds are applied to prepare polymer-dispersed liquid crystal (PDLC) films and the role of the hydroxy group is studied in detail by comparing the effects of the hydroxylated acrylate monomer, the hydroxylated mesogenic component and their corresponding non-hydroxylated components. It is revealed that the hydroxylated acrylate monomer plays a more important role in modifying the morphology of the polymer matrix and thereby the electro-optical performance of the PDLC films. Parameters of the polymer matrix, such as size and density of voids, can be affected by various components, but only the hydroxylated acrylate monomer can alter its type from the typical Swiss-cheese type to the polymer-microsphere type. Essentially, the hydroxylated mesogenic component takes effect through changing the ratio of the liquid crystal phase, while the hydroxylated acrylate monomer can participate in the polymerization and impact the development of the polymer matrix. It is anticipated that this research can help in understanding the role of the hydroxy group in PDLC films.